METHOD AND APPARATUS FOR THE DETERMINATION OF REGENERATIVE BRAKING CAPACITY IN A VEHICLE WITH A STEP-GEAR TRANSMISSION

摘要

A powertrain system including an internal combustion engine, a transmission and an electric machine is described, and includes the electric machine rotatably coupled to a crankshaft of the internal combustion engine. The transmission is coupled to a driveline to transfer tractive torque and braking torque thereto. A method for controlling the electric machine includes determining a short-term axle torque capacity, a long-term axle torque capacity and a maximum regenerative braking stall torque capacity, and determining an operator request for braking. A preferred regenerative braking capacity is determined based upon the short-term axle torque capacity, the long-term regenerative braking capacity, the engine stall regenerative braking capacity and the operator request for braking. Torque output from the electric machine is controlled based upon the preferred regenerative braking capacity.

主权项

1. A method for controlling an electric machine disposed to generate tractive torque in a powertrain system, wherein the powertrain system includes the electric machine rotatably coupled to a crankshaft of an internal combustion engine that is coupled via a torque converter to a transmission, and wherein an output member of the transmission is coupled to an axle of a driveline, the method comprising:
determining a short-term axle torque capacity, a long-term axle torque capacity and a maximum regenerative braking stall torque capacity; determining an operator request for braking; determining a preferred regenerative braking capacity based upon the short-term axle torque capacity, the long-term regenerative braking capacity, the engine stall regenerative braking capacity and the operator request for braking; and controlling torque output from the electric machine based upon the preferred regenerative braking capacity.